reb78 Posted June 12, 2018 Share Posted June 12, 2018 I have had a number of gearbox leaks for a while now. Topping up fortnightly has kept on top of the levels (they dont lose much) but its consistently wet with oil under the vehicle. At the weekend, I dropped the overdrive and transfer box again and have solved all but one leak. I am still getting a small amount of ATF weeping down the join between the main box and the transfer box. To date I have tried several new seals, last weekend, I changed the collar the seal runs on and the o ring it slides over along with a new seal again. The seals are good quality (corteco or that level). There is a grub screw in the rear LT77 casing, but I have sealed this with silicone so dont beleive it can be that. The breather is clear. I am drving the seals in so that they are just beneath the level of the main box - i.e. the outer edge of the seal is flush with the chamfered edge of the hole it sits in. Any ideas? My drive is a mess with oil drips and I would like to solve this once and for all! I need the vehicle daily too so box off and send off is not really an option I want to take. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 12, 2018 Share Posted June 12, 2018 You think it could be this? Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 12, 2018 Author Share Posted June 12, 2018 No. I wish it was. That was one of the leaks before this weekend, but we solved that temporarily whilst the boxes were off at the weekend with yet more sealant worked into the shaft hole. I am going to get another box sleeved and rebuild it to permanently solve that problem. I am as sure as i can be that this is ATF. Its driving me nuts and there is a limit to the number of times I want to take these boxes off and back on again in the same day! This is the fourth time in a year that we have tried to solve this! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 12, 2018 Share Posted June 12, 2018 That thread mentions one bolt not going into a blind hole, and potentially being a source of a leak, did you use thread sealer on the bolts? Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 12, 2018 Author Share Posted June 12, 2018 I used PTFE tape - they arent leaking at the moment, but agree they have the potential to do so. Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 12, 2018 Author Share Posted June 12, 2018 Keep the ideas coming though! Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 12, 2018 Author Share Posted June 12, 2018 I am worried that the gearbox mainshaft is ever so slightly out of line or the seal is not in entirely square, but i would have thought both of these would be difficult to achieve even if you were trying! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 12, 2018 Share Posted June 12, 2018 Agreed, unlikely to be a seal, they need to be quite a way off to leak, and I doubt you are that inept after doing it 4 times Only real way is to loosen and slide back, brake clean, go for a really short drive and loosen again to see where it is coming from. Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 12, 2018 Author Share Posted June 12, 2018 I ran it on the ramp with the transfer box removed and it seemed good by that seal. Its proving a hard one to track down, but there is definitely red oil running down between the transfer box and main box. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 12, 2018 Share Posted June 12, 2018 Yeah, I think a drive is key though, gets oil up to temperature and also sloshes it around to get where it won't be when you are on a ramp. Quote Link to comment Share on other sites More sharing options...
pat_pending Posted June 12, 2018 Share Posted June 12, 2018 3 hours ago, Bowie69 said: Agreed, unlikely to be a seal, they need to be quite a way off to leak, and I doubt you are that inept after doing it 4 times Only real way is to loosen and slide back, brake clean, go for a really short drive and loosen again to see where it is coming from. Do this, but once everything is clean and dried, give it a good dusting in talcum powder before bolting it up. When you drop it apart again the source of the oil should be easy to track in the powder. 1 Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 12, 2018 Share Posted June 12, 2018 Like it @pat_pending Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 13, 2018 Author Share Posted June 13, 2018 This has been under there for a few days poked in that circular ‘drain’ hole in the transfer box casing. Is it red atf or used ep90? To my eye it looks red Quote Link to comment Share on other sites More sharing options...
Giles Posted June 14, 2018 Share Posted June 14, 2018 I thought ep90 had a very distinctive smell ? Tried sniffin'? Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 14, 2018 Author Share Posted June 14, 2018 I can never really tell oils apart on smell! I did have a sniff last night but im none the wiser!! Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted June 14, 2018 Share Posted June 14, 2018 ATF smells sweet to me, but EP90 is quite an astringent smell. Couldn't say from colour on a screen. Quote Link to comment Share on other sites More sharing options...
monkie Posted June 14, 2018 Share Posted June 14, 2018 That picture looks like ATF to me, but have you tried blotting a spot of ATF and a bit of EP90 on some paper either side of sample from the leak? It might show a helpful comparison. If that doesn't help, you can get fluorescent dyes to add to the gear box oil. Never used them myself but might be worth a try? https://www.ebay.co.uk/i/302701362993?chn=ps&adgroupid=51456964475&rlsatarget=pla-429319282044&abcId=1130086&adtype=pla&merchantid=118934974&poi=&googleloc=1007265&device=c&campaignid=1029031424&crdt=0 Quote Link to comment Share on other sites More sharing options...
cackshifter Posted June 14, 2018 Share Posted June 14, 2018 OK, another thing you might do if you are desperate (you do sound a bit desperate) is to pressurise the box slightly through the breather, while it is on the ramp - that might be enough to make it leak more rapidly and let you spot it. Quote Link to comment Share on other sites More sharing options...
reb78 Posted June 14, 2018 Author Share Posted June 14, 2018 1 hour ago, cackshifter said: OK, another thing you might do if you are desperate (you do sound a bit desperate) is to pressurise the box slightly through the breather, while it is on the ramp - that might be enough to make it leak more rapidly and let you spot it. I think i will try this (and the talc idea) next. It will be a few weeks before i can be bothered to remove the transfer box again though! Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted June 16, 2018 Share Posted June 16, 2018 I have a nice LT77 that doesn't leak, Rich 😉 Mo Quote Link to comment Share on other sites More sharing options...
DC_ Posted July 21, 2020 Share Posted July 21, 2020 Resurrecting this thread....... did you manage to source the trouble of the leak @reb78 ? I seem to have a slight ATF leak very similar to yours Quote Link to comment Share on other sites More sharing options...
reb78 Posted July 21, 2020 Author Share Posted July 21, 2020 Hi DC - sorry, my answer probably isn't what you want to hear. This box had to come off every two years on average for various faults (failure to engage reverse, difficult to engage 1st, leak from front cover gasket, layshaft bearing failure, leak - that no-one ever managed to fix properly above). It always went back to the company I bought it from who fixed it (never fixed the leak) at cost each time but of course that didn't involve any form of recompense for the days to remove, days to replace and the time off of the road in between. This leak was followed by yet another failure where the 1-2 syncro spacer appeared to have cracked in half and the input shaft pinion bearing also failed. The box was a disaster from day 1 so I gave up on it and came to an agreement with the supplier that if they bought the box back off of me I would take my trade elsewhere.... Bristol Transmissions built a stumpy R380 for me so that cured the leak from my point of view! I just hope my old box wasn't 'rebuilt' and passed on to someone else. A few of us wondered if the main and extension housings had been mixed up on the LT77 above as they should stay as matched pairs as I think they are machined together before they are built so ensure shafts etc are aligned. A slight misalignment could potentially cause the leak, but I never got to the bottom of it. The R380 I have now has been good so far! 1 Quote Link to comment Share on other sites More sharing options...
western Posted July 21, 2020 Share Posted July 21, 2020 I've had a stumpy R380 since mid 1994, the first on failed when the layshaft bearings went leaving me with 1,2,3, & 4, no reverse or 5th. replaced by a Ashcroft unit about 12 years ago, its been fine, much prefer the R380 over the LT77. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted July 21, 2020 Share Posted July 21, 2020 I've never had a stumpy R380. Oh the shame ... Mo 😁 Quote Link to comment Share on other sites More sharing options...
DC_ Posted July 21, 2020 Share Posted July 21, 2020 Thanks for the details @reb78 appreciate it. My box has always been smooth and I do change the ATF regularly (probs more than needed). I’m not allowed back to work yet so have another couple of weeks free. I might as well drop the RT230 transfer and have a look. It seems like a mix of EP90 and ATF to be honest. I laughed today when I was sniffing the oil. For me ATF smells like strong B.O. 😂 Would a stubby R380 fit a 2.5na and RT230 tranny? 🤔 Quote Link to comment Share on other sites More sharing options...
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